Since GLUT1, GLUT2, GLUT3, GLUT4 are all expressed at different levels in RCC and they are all capable of transporting glucose [40], it is highly possible that in our system the loss of GLUT1 led to compensatory up-regulation of another glucose transporter which led to worse outcome, while STF-31 was able to inhibit the whole family of glucose transporters to inhibit tumor growth. This evidence concerns the gene SLC2A2 and renal cell carcinoma.